Measuring instrument



Nov. 8, 1927.

' 1,648,643 E. HART ET AL MEASURING INSTRUMENT Filed Aug. 25. 1925 3 Sheets-Sheet 1 I /io grvuenl o'm 06039630211 sch I.) g v abtonwq Nov. 8, 1927. 1,648,643

E. HART ET AL MEASURING INSTRUMENT Filed Ausz. 25. 1925 3 Sheets-Sheet 2 Nov. 8, 1927.

1,648,643 E. HART ET AL MEASURING INSTRUMENT Filed Aug. 25, 1925 3 Sheets$heet 5 'BGISUIU 'HGISNI Patented Nov. 8, 1927.

' w re MEAfiUBING- INSTRUMENT. v I

Application filed August 25, 1925. Serial No. 52,382

The present invention relates to measuring vinstruments and has for its object to provideanimproved optical instrument for determining the distance between two points otan object to be measured and embodies contacting portions for engaging the object and improved indicating means by which the results are read directlyirom the instrument. .iThe particular form ofthe invention disclosed embodies a, measuring instrument,

having relatively movable parts,-such as the arms or jaws of a pair of calipers one of which carries'a scale, having any suitable imarkingsithereon, and'the otlrerhaving an 1.5 index and an objective for viewing the scale,

'. thelatterbeingv preferably formed of transparent or translucent inaterialand so disposed thatlight will be admitted there- :throughalongthejoptieal axisof the ob 0 jective, whereby the instrument maybe-more accurately read particularly under adverse {lighting CQIlClltlOllS;

A further ob ect of the invention is to provide :an improved measuringv instrument of, the I type described embodying. enclosed and sealed indicating parts, whereby the same arecprotected against drrhgrease and other foreign substancesdetrimental to the useoi ,tlie instrument I I I I I AtI tner object ofthe invention isto provide a, measuring instrument of the char- "acterl described; embodying simple form of i construction afiording" ahighly etlicient instrument, which is both convenientto operate 7 and comparatively inexpensiveto inanutactime To these and other ends the invention resides in certain improvements and combinationsotparts; all as willbe hereinafter more Jfully' desei ibedj the novel features being pointed out inthe claims at the end of the specification. I l r .111 the drawings: I

Figured is aiplanview of an instrument 45, embodying one form of theinvention.

' Figure 21s aside elevation of the same I -Figure 3 is an enlarged sectional elevation taken on line of- Figure 1., I

T Figure" 4: is a detailed'jplan.view of the scale carrying section of the instrument.

Figure 5 is a detailed vplan of thebearing plate'jfor pivotally supporting one of the movable sections ofthe instrument;

* "';Figufe6: is an enlarged plan of a portion of the scale as viewed through .theeye piece.

DWIN Hear A ND seen-en B. GALLAsoi-r, er noorrnsrzm, NEVJ Y0BK,'ASSI GNOIRS T0 7 Bursona LO MB orrronn contrary; er nocrrnsr sa, new m;rcoammma Figure 7 is an enlarged sectional view taken on line G6f of Figure 1 I i Figure 8- is a detailed view drawn to an enlarged scale and illustrating thejmanner of mounting the cylindrical contacts for the outside caliper jaws, and i Y i Figuref) is a view of theqpart shown in Figure 8, taken at a different angle.

Similar reference numerals throughout the severalviews indicate the sameparts. i i 'The present im'entionembodiesa measuring instrument adapted particularly for use both as an inside and outside caliper with improved means whereby the; different measurements taken from time to time m ay be readily viewed upon holding-the objective not the instrument between the eye and a, W111- dow or other illuminated area. i

I It is also particularly advantageous either I for inside or outside measurements where the natureof the object to be measured is. such that the instrument cannoube withdraivn from measuring position.without changing the relative position of'thejaws, Incases of this kind with the; present instrumenflthe reading is taken before attemptingto ivvith drawtheunstrument from contact with the part to be measured. This, feature attordsf a marked improvement over the ordinarytype of caliper. I u

A particular adi antage. afforded byjthe Iuse of the optical means disclosedis that relatively large measurements may be taken with bnt httle increase in the-diameter; of thesectrons ,surroundingthe pivotal point of the instrument, Thisis madefpossible by I I the use of a relatively smallfscale adjacent said pivotal point, preferablyone having readings not visible to the naked eye, but.

which are clearly visiblejthroughthe objec 'tive prov ded, which itself is of relatively small. proportions. Thus a ten or tw lve inch caliper, .or evenz ,s izes consider bly larger, mar ave .r du ei ele. 0 s m thing like an nchi'n length t iliirm t of a relatively small diameter for thee liecarryi'ngportionof the instrument.

; I Reterring to the clrawings; {10 and @11; repcalip'ers while 12 and 13, r preseaathejer'ms resent I the arms or jaws I .offlithet'plitiside or"; the inside calipers; arm 12; being; mtegrgal ar S hOW 'i fes ed; i i integral Wltl1 arm '13; ae end; at

Figure 1. Arms 10 and 12 project from a circular scale carrying section 15 of the instrument and arms 11 and 18 project from a circular section 16, rotatably mounted .upon the section 15.

Interlocked with the circular section 16, as by means of the pins 17 is a disc 18, having a screw threaded post'19, carrying a locking member 20, preterablyin the form of a lever. The lever engages a washer or clamping ring 91, resting upon the circular portion 16' andiby moving the lever substantially tothe full line position shown in Figure 1, the sections 15 and 16 will be clamped by the disc "18 against relative movement. lVhen the lever is in the dotted line position shown in Figure 101' against the stop pin 22, the sections are 'ireeto r0- tate, one uponanother: The disc 18has 'innernndouter annular-shoulders 23 and 2 1 and a bearing portion 25 upon which the section 15 is adapted to rotate in addition to its bearing upon the inner face of the section 16. The bearing 25 is relatively "large and insures proper alinement of the parts.

.Th e annular section 15 is recessedto receive the ti'ansparent scale carrying ring 26, 1

"eitherbe ininches or'millimeters.

Theannular recess formed in thesection 15 islarg'er than the scale rlngin order to "permitthe latter to be properly centered with respect to the'pivotal aXis of the instrument. This is preferably done by a series of radially-disposed adjusting screws 29.; projecting into and engaging the outer periphery of the scale ring, as shown in Figures 3 and 41-. After thescale ring has been properly centered, a clamping ring therefor is screwed into position upolrthe annularsection 15, as shown in Figure 8. A filler 31, preferably cement or other ad- "hesive material is interposed between the scale andclainping ring which when-hard.- enedforms a. suitable binder between said "parts. Rotation or the clamping'ring 30- into retainingposition is preferably affected a suitable tool, having projections adapt ed to be inserted in the recesses 32 of the he objective or eye piece for reading the isprovided with a suitable magnifying lens33," disposedin a holder 3 1 threaded in a casing 35 [having an inwardly extending flange 36, ,uponfwhich thelens is adapted to rest, as shown in Figure 31 The casing 35 is screw threaded upon a tube ormount 37 which in turn is threadedly connected with nension.

4A- of the mount,.to. permit the bottom of the glass rod to be accurately adjusted into close proximity to the scale plate 26, as

shown in Figure 3. "The-bottom of therod has formed thereon a suitable index for both scales, as shown inFigure 6. It is also 1 preferably provided with n the ords In side and Outside, disposed respectively at points opposite the scales for the inside andoutsidecalipers. j I

With the instrumentclosed, as indicated by full linesin Figure 1, the index mark "45 will be in registry withthe zero point of the scale 28 for the outside caliper; 1 However, for the inside caliperthe distance between the contact points 16 thereof has'to be taken into account, and this the present case being preferablyinade equal'to one-quarter of an inch, the scale forthe inside calipers has beeninarlred QCCOICllijlglY asshown in Figure 6. Forexample, if the actual distance between the two points to bemeasiired is .35

cut

of an inch the index line-will coincide with a lineon the scale corresponding to this di- In the present construction, the scale plate 26 is entirely enclosed and sealed sorthat no dust or dirt'can accumulate thereon to interfere with the readings. Likewise the inner. end of the. glass rod carrying theindex is protected againstthe accumulation ofdust' ordirt. The rod servesas: a sealing member for the mounta-nd should anydust or foreign particles accumulate on its outer end 1 they may be easily wiped ofl' upon removing the lens holderi34i I H Light is admitted to thetransparentscale plate. through an opening 17 in the annular portion of the. scale carrying section 15fand through a window embodyinga glass plate 48 in the disc or clamping ring- 18, the window being located in registery with the;

eye piece! "The index is adaptedto register with thezero point when the contact points 19 of the outside calipers are inengagement as shown in Figure-1. These contacts are preferably in the form 1 of j hardened cylin ders forced into recesses formed in the ends of the arms 10 and 11 u1'1'(ler pressure and. when worn may be driven out and turned"so.1as

to again'aiford the proper readings-,or: if de- ;siredfthey may be replaced with new contacts from time to time. i 1

The'contacts 46 for the inside-calipersare preferably in the form of hardened steel balls and are mounted in recessesi50 formed in the ends of arms12 and 13 and held in position zby the -screwplugs 51 ;as shoWn in 'Figur-GT. "When the surfaces ottheba lls ,lwh-ich contact withthe 1 objects to j be, measuredbecome worn the plugs may-be loosened iandathe *bfl'llSi'DLlIIlQCl irrtheir bearings so that the correct distance will be afiorded between the outer. faces.ot the-balls.

r The lens 33 vmay be iproperlylfocusedby adjustment ofthe casing 35 on the mount ,wSlll (JB relativelyv coarse threads are pro- --vided'.-betweensaidparts, one of the threads being cutaway 'for,-aqportion ,of its circumzference- EOIfOIm-agLOOVG for the reception of .a' limiting SCIGWJEJQ adapted to engage a shoulder on the mount 37 atithe endfoi the --groove tolimit the outward movement ofthe casing '35.

i l-he, extentito which the calipers may be opened is (preferably limited by a pair of 20 tan-gular1y1d 'sp0s stop pin .5 a d as, the n ormenp oj ct ng-flow t e m l0, an th latter trom1the annular portion I 16 of the objective-carrying section. otthe instrument. The eye piece may bereadily adjusted to br ngrthelinde iinto esi t ry i t Zero unar since'it'hegheads and, shanks of the screws 58; in the base plate 138; lie within .L pe ings t 2 ne erei j a ns reat r d vanreters than those got the headsand shanks, So it v V v ,thr-ea( liedz into ,the annular, section 16 upon whie rth eyenie ei m unted f RVhile,the pnesent disclosure embodies both mi l-S an A r 1 s .1.t,; W1 1de t Q th t r r'n be separately ,embodied in a singleins etr a t,l isles ted, with md a ps r m th rinci alesiof the invention. v V Vile,clai nr as,ourinvention: g V 1, In, measuring,,instrument, tbBlCQlY lblnatiolijvitli apair of adjustably connected ineiiibers, adapted. itor 7 engagement with an 1, ject {til-J36 measurechbf a scale 'carried b y .Qiie o f said ne nlge rs and, anhbjective ar i y inte er-e memb r a ein ad s y able- 7 an axis extending ti ansverse to i the scalcland adapted to ,fo'rm an image of the iscale in, all positions of j the ,niembers within 3 predetermined limits, and an index on ul the ,ohj actives-carrying ,inember.

2- timnea mi g in rument; th Qm nationwith a pair or .spiv otally connected ject to be measured, of a transparent member carried byone of the arms having a scale tormed thereon and ocular means carried by the other arm having an index associated therewith, the scale being illuminated by light admitted through. the transparent member; V

3; In a measuring instrument, the combination with a pair of pivotally connected arms adapted for engagement with an ob-. ject to be measured, of a transparent scale 65 disposed on one of the arms thelatterhaw eingv understoo d that" the screws are I ing an pen .g fo a m t ng li th scal means fo sewing thewle upe sai rea a eye p e eea r e tin,v he ethe r through which the scale is ,adaptedgto riewe an in e a v s l $1 29 e i the eye-piece, elatir i owh hithe qa e iiip e to rmw-e- 1 4. 11, 1 m asurin v1ins e t h wm iiiat w t {pai ed p vb a f y c n c d far sadapte :e ae lemw tb mee to-,be measured, a plate sp aced 'from,and. c o,n nectedwith one of the arms anarQrfmingre taining means for the otherijarm, atransparent; plate; carried by,.the lastamentioned ,arnrl aving a scale thereon, an eye piec carried by the-other arm having i an index ss0- ciated with the scale, a11dla window iiil the retaining v 1 e for admitting light ,to the Sc lp A. r v 5p Ina measuring, instrument,, the combi nation with a, pair of vjpivotallyj c ,(lfliieiited arias, adapted, for, engagement with an i ob- ;ject .to be .measured a ure carriedby gone otsairt arms ha ving:v a scale thereon, and'..an

,ol ijective disposed in registrywith the 1;

including a ,lens; and fa transparent .nieinbier interposed be tween the scale: and the lens ijof I the o bjective and an indezi overlying .v the sc ale. v v V I i v ln a measur with a ,p air-,- ot ,pivotally connectedj arms ,outside calipers in one ,instrudirnls '1.. r 11H J, i I K securing said plate to, said arm, a Lens ube d spose siren-th ehwrm'in b-i 'iyc it ,thescalefa.magnifying;lens ca fried tube,;,a.1'r a glassjro d disposed fwithin the tube betweenthe lensj andthe scale andhaw uii sienrind e et r yj ei h l's'c ns mb es ien am a u' i s 1 "ep dr ne. a Pai ;etar al s pp it y disposed annular port ons providednwijth li ies en r e gm hscifene sits' b said annular ;po and having]ajp vot Past i i st s flu-P s aid p ni gs n l prming a pivot [for one of pilgri a n 'em threa'ded'nppn said post and forming leek- .1%,? e ,i'or secur ng the arnis'f in' i t pro ition s of lad" 't'ment, v alscal'e Holdinginstrument, a combine;

nstr ument ried by'one of said members having a scale thereon; a magnifying lens carried bythe other member and a light transmittlng elehaving an indenthereonQ V 10. Ina measur ng instrument, the comment between the lens and said element bination of a pair of pivotally connected arms one ofiwhich is provided With an open ing a transparent member aligned With the openingand having a scale thereon, a mag nifying lens carried by the other arm opposite said'opening and an index disposedbetweensaid lens and transparent member;

11. In a measuring instrument, the com "bination of pair of pivotally connected arm's one jof vhich isprovided with anfopen ingfa' transparent member carried by the a l ast mentionedarm in alignment with the nifyinglenscarried by the other arm opposite said opening, and a light transmitting element disposed between said lens and transparent member and having an IDClGX thereon; i

12. In a measuring instrument, the com- 'binationofa disc, a pair ofrelatively movher, a magnifying lens disposed opposite an able arms, "one of which is-fixed to thedisc' andt'he other pivotedupon the disc, a transparent memb r enclosed between said disc andonje of said arms and having a scale thereon, the-disc having opening for admitt-ing light to the said transparent menijopening in the other arm in registry With :the iirist mentioned opening and a light transmitting element closing the second menioned openingandhaving an index thereon forcooperation Withsaidseale. V f13qIn ameasuringinstruinentfthe combination ofa disc, a pair of relatively movable arms, one of which is fixed to the disc and the otherpivoted. thereon, a transparent member enolosedbetvveen sai-d 'disc and one or saidarms and having a scale thereon, the

disc having anopening for admitting light to said transparent "member, a light transmit-ting element closing said opening, a magnify ng lens disposed opposite anopening a in the other arm-in registry; with the first =bination With a pair of arms havingfpivotally connected circular "hub portions, of 5 means for indicating the degree of move mentoi' one arm relative to the other in:

cluding a plate mountedkupon one of said hub portions and having ascale thereon and a i an eyepiece upon the other hub portion for Q} v ewing the scale.

In a measuring instrument, in combination, a disc, a pair of arms having 011'- cular hub portions, one of which is fixedto said "disc and the other" pivoted thereon and in cans for indicating the degree of movement of one arm relative tothe other including a scale disposed between said disc and one of said huh portions and an eye by the other hub portion; 3 i

16. In a Incas -piece "carried 8 uring instrument, "the 1 combinationof a pairoffpivotaHy connected open ngand having a' scale thereongamagarms having circular hub v portions,. one of the otherwvith anopening; an-eye-piece inf eluding an index, said eye-p ece bemgadaptedto form a seal forsaid opening, atransthe first meritionedopening for admitting l ightto the scalefl I 17.111 afmeas'uring -instruxnent, in combination, adisclhaving hearing formed thereon, an arni' l1aving acircnlarportion rotatable upon said bearing and having an annular recess formed therein, atransparent fring disposedfwithinl said recess, meansiorf centering tliering with respect to -the axis of the disc; a second arm havingfa circular portion fixed to thedisc and overlyingfthe {circularportion of theti -st mentioned arm and having an opening in registry Withsaid" scale plateliaving an indexfthereon anda light transmitting element-disposed in an a EDWIN HARTC y GEORGE eesawthereon for cooperation which. is provided with a circular. recessand l lens andaglass-rod between the'lens and ring, an eyepiece including "a magnifying 

